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Lanthanide permanent magnets are widely used in applications ranging from nanotechnology to industrial engineering. However, limited access to the rare earths and rising costs associated with their extraction are spurring interest in the development of lanthanide-free hard magnets. Zero- and one-dimensional magnetic materials are intriguing alternatives due to their low densities, structural and chemical versatility, and the typically mild, bottom-up nature of their synthesis. Here, we present two one-dimensional cobalt(II) systems Co(hfac)2 (R-NapNIT) (R-NapNIT=2-(2'-(R-)naphthyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, R=MeO or EtO) supported by air-stable nitronyl nitroxide radicals. These compounds are single-chain magnets and exhibit wide, square magnetic hysteresis below 14 K, with giant coercive fields up to 65 or 102 kOe measured using static or pulsed high magnetic fields, respectively. Magnetic, spectroscopic, and computational studies suggest that the record coercivities derive not from three-dimensional ordering but from the interaction of adjacent chains that compose alternating magnetic sublattices generated by crystallographic symmetry.

Der 3D‐Druck von geometrisch komplexen Nanostrukturen ist auf dem Weg zu ersten Anwendungen. Die Auswahl an geeigneten Materialien ermoglicht metallische, halbleitende, isolierende, supraleitende und exotische magnetische Eigenschaften. Das 3D‐FEBID‐Verfahren schreibt mit dem Elektronenstrahl eines Raster‐Elektronenmikroskops wie mit einem Nanostift. Das Material wird als Gasstrom von Precursor‐Molekulen uber eine Hohlnadel zugefuhrt. Der Elektronenstrahl ermoglicht die hochlokale Fragmentierung dieser Molekule, die meist metallische Zielatome enthalten. Die lokale Verweildauer des Strahls steuert den Strukturaufbau in der Vertikalen, wahrend seine seitliche Bewegung zu geneigten, freistehenden Strukturen fuhrt. Eine Herausforderung ist die definierte Strahlsteuerung, um ein CAD‐Modell moglichst prazise in ein reales 3D‐Nanoobjekt zu uberfuhren. Fur die Zukunft soll eine simulationsgestutzte Software zur Steuerung des Elektronenstrahls auch Laien die Anwendung erleichtern. 3D‐FEBID ist bereits heute ein zuverlassiges und in vielerlei Hinsicht einzigartiges Verfahren zur Direktabscheidung funktionaler Nanostrukturen.

The crystalline phases of YbBr2 were investigated by powder neutron diffraction between 1.5 K and the melting point at 955 K (682 °C). The low temperature SrI2 phase is observed up to 550 K, the α-PbO2 phase between 260 K and 750 K, the CaCl2 phase between 690 K and 790 K, and the rutile phase from 790 K to the melting point. All observed phase transitions are first order, except for the second order CaCl2 to rutile transition. The transition temperatures and enthalpies were determined by differential scanning calorimetry.

The thermal expansion and phase transition of PrBr3 was investigated by neutron diffraction and DSC measurements. PrBr3 has a low-temperature (LT) UCl3-type modification and a high-temperature (HT) PuBr3-type modification. The stability range and structure of the HT phase were established for the first time by diffraction experiments. The thermal expansion of the LT modification was investigated by powder neutron diffraction from 1.6 K to 940 K. It shows a very anisotropic expansion of 3.5 % along the a-axis up to 940 K, but along the c-axis a small expansion of 0.14 % up to 445 K is followed by a contraction about 0.4 % up to 940 K. On heating, the LT phase is observed up to the melting point at 962 K. A partial transformation to the HT phase takes place above 956 K. On cooling, the HT phase crystallises from the melt at 946 K and transforms to the LT phase at 930 K.

The ternary uranium(III) halides A2UX5 (A = K, Rb; X = Cl, Br, I) have been prepared from the binary components AX and UX3 in sealed tantalum containers. According to their Guinier X-ray powder patterns, they all crystallize with the K2PrCl5/Y2HfS5 type of structure. Lattice constants for ambient temperature are reported. Single-crystal structure refinemens were undertaken for K2UI5 and Rb2UCl5. Magnetic susceptibility data were recorded with a SQUID magnetometer from liquid helium to room temperature. One-dimensional (intrachain) and three-dimensional antiferromagnetic ordering occur at low temperatures dependent upon the U3+U3+ distance. Absorption spectra were recorded between 4 000 and 28 000 cm−1. They show f—f transitions typical for U3+ and, depending on the halide, very strong f—d transitions above 14 000 to 15 000 cm−1, respectively. Synthese, Kristallstruktur, Magnetismus und Absorptionsspektren von Halogeniden des Typs A2UX5 (A = K, Rb; X = Cl, Br, I) Die ternaren Uran(III)-halogenide A2UX5 (A = K, Rb; X = Cl, Br, I) wurden aus den binaren Komponenten AX und UX3 in verschweisten Tantalampullen gewonnen. Nach Guinier-Aufnahmen (Raumtemperatur) kristallisieren sie samtlich im K2PrCl5/Y2HfS5-Typ. Einkristall-Strukturverfeinerungen wurden fur K2UI5 und Rb2UCl5 unternommen. Magnetische Suszeptibilitatsmessungen erfolgten mit einem SQUID-Magnetometer von Raumtemperatur bis zur Temperatur des flussigen Heliums: Eindimensionale (innerhalb einer Kette) und dreidimensionale antiferromagnetische Ordnung wird bei tiefen Temperaturen, abhangig vom Abstand U3+U3+, beobachtet. Absorptionsspektren wurden zwischen 4000 und 28000 cm−1 aufgenommen. Sie zeigen die fur U3+ charakteristischen Ubergange und, abhangig vom Halogenid, sehr starke f—d Ubergange oberhalb 14000 bzw. 15000 cm−1.

The compound Tb 2 C 2 I 2 crystallizes with a layered structure (space group= C2/m ), which has a close-packed arrangement of I–Tb–Tb–I slabs. C 2 units are located within the Tb octahedral voids. Powder magnetic susceptibility measurements suggest two antiferromagnetic ordering transitions below 90 K. From the refinement of neutron powder diffraction patterns, the Tb moments order with a propagation vector k =(0,0,0). The refined Tb moments are 8.0(1) μ B at 10 K, and they are aligned antiferromagnetically in the ac plane.

Alkali borohydrides MBH[4] and their deuterides have been investigated by X-ray and neutron powder diffraction (M=K,Rb,Cs) and by infrared and Raman spectroscopy (M=Na,K,Rb,Cs). At room temperature the compounds crystallize with a cubic high temperature (HT) structure having FM[3]M symmetry in which the [BH4][−] complexes are disordered. At low temperature (LT) the potassium compound transforms into a tetragonal low temperature structure having P4[2]/n mc symmetry in which the [BH4][−] complexes are ordered such as in the isotypic sodium congener. The B---H distances within the complex as measured on the deuteride at 1.5 K are 1.205(3) Å. Indications for a partial ordering in the rubidium and cesium compounds exist but are not sufficient for a full structural characterization. Infrared and Raman spectra at room temperature are fully assigned for both hydrides and deuterides, including the overtones and combination bands, the Fermi resonance type interactions and the [10]B to [11]B splitting due to the presence of natural boron in the samples.